Device for folding paper board blanks



Sept. 11, 1962 H. BLUMER 3,053,151

DEVICE FOR FOLDING PAPER BOARD BLANKS Filed June 13, 1960 2 Sheets-Sheet1 Ha s 5/ 0 er Sept. 11, 1962 H. BLUMER 3,053,151

DEVICE FOR FOLDING PAPER BOARD BLANKS Filed June 15, 1960 2 Sheets-Sheet2 29 7 l I f 3 97A Isk mi I H v l I a El 9 A Z6 25 Z? 23 27 /.9

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United States Patent Ofifice 3,053,151 Patented Sept. 11, 1962 3,053,151DEVICE FOR FOLDING PAPER BOARD BLANKS Hans Blumer, Zurich, Switzerland,assignor to Steiger A.G. Lithographic, Druckerei, Cartonnagefabrik,Bern, Switzerland Filed June 13, 1960, Ser. No. 35,625 Claims priority,application Switzerland June 18, 1959 7 Claims. (CI. 9351) Thisinvention relates to improvements in means for erecting boxes from paperor cardboard blanks and, in particular, is directed to a new and noveldevice for folding blanks into rectangular type boxes.

,The device of the present invention is particularly, though notexclusively, designed for folding a box having a rectangular bottom,upstanding opposed end walls and upstanding opposed side walls, the sideand end walls being connected to the bottom by fold lines. The box,further, includes a tab on the ends of each side wall, the tabs beingconnected thereto by hinge lines and being positionable at right anglesto the side walls and extending inwardly toward the end walls. The tabsterminate at their free ends in upstanding locking projections and areadapted to be positioned through vertical slots formed in the end wallsadjacent the end portions thereof. The end walls are also provided withupwardly projecting flaps which are connected by fold lines to the upperedges of the end walls. The flaps extend above the coplanar upper edgesof the end walls and the side walls and are adapted to be folded overunder a lid or cover which is hingedly carried by the upper edge of oneof the side walls. The slots extend into the flaps and the lockingprojections fit through the slots in the flaps and are adapted to befolded over when the flaps are bent over under the cover.

The device of the present invention comprises a stationary part and adie or moving part cooperating therewith. The stationary part provides arectangular opening through which the die passes in erecting the boxfrom a blank. The stationary part includes a first pair of parallel,laterally spaced bending rails and a second pair of parallel, laterallyspaced bending rails, the rails of the second pair being disposed atright angles to the rails of the first pair and being positioned invertically spaced relation thereto. The upper pair serves to bend overthe end walls provided with slots and the tabs of the side walls. -Theupper pair of rails carries a plurality of spring urged balls which aredisposed normal to the path of movement of the die and which arepositioned in depending relation to the rails of the first pair. Certainof the balls are arranged directly below the bending rails of the upperpair and serve to push the portions of the end walls that lie outside ofthe slots into corresponding recesses in the die so as to open theslots. The rails of the lower pair serve to fold up the side walls andforce the tabs into the slots. Certain of the balls lie substantiallywell below the rails of the first pair and substantially in the plane ofthe rails of the second pair. They serve to counteract the tendency ofthe holding projections to slip out of the slots.

Thus, the primary object of the present invention is to provide a devicefor easily and quickly folding cardboard blanks into box formations bycausing the foldable side and end walls to be folded into erectedpositions and locked in their box form.

A further important object of the present invention is to provide anadjustable structure wherein the rails are interconnected and are joinedin an adjustable manner so that the rails of each pair can be movedlaterally closer or apart and the pairs of rails can be verticallyspaced in an adjustable manner whereby boxes of various sizes can beerected.

The foregoing and ancillary objects are attained by this invention, thepreferred embodiment of which is set forth in the following descriptionand illustrated in the accompanying drawing, wherein:

FIGURE 1 is a perspective view of one form of box erected by the deviceof this invention;

FIGURE 2 is a vertical sectional view of the box erecting device and istaken on line 22 of FIGURE 3;

FIGURE 3 is a top plan view of the box erecting device;

FIGURE 4 is a vertical cross-sectional view taken on line 4-4 of FIGURE3, and,

FIGURE 5 is a detailed vertical sectional view of the interconnectingmeans between the pairs of bending rails and is taken on line 5--5 ofFIGURE 4.

Referring now more particularly to the drawings and, initially to FIGURE1, the box, which is representative of the type of boxes for which thepresent device has been designed, includes a rectangular bottom 1 andopposing side walls 2 and opposing end walls 3. The side and end wallsare connected with the bottom by fold lines. Each of the side walls hasat its ends a tab 4 which is hingedly connected thereto and which ispositionable at right angles inwardly towards the end walls. Each tab isprovided at its free end with an upstanding holding projection 5. Theend walls 3 are provided, adjacent their outer ends, with vertical slotswhich are adapted to receive the tabs 4 and projections 5. The end wallsare provided at their upper edges with flaps 3b which are connected tothe upper edges by fold lines. The flaps are adapted to lie under thecover or lid, when the cover is closed and the flaps fold over theprojections 5 to lock the tabs securely in the slots.

The device for erecting the box of FIGURE 1 is shown in FIGURES 2-5 andincludes a stationary part A and a die or moving part B which cooperatestherewith for erecting the side and end walls 2 and 3 of the box. Thestationary part provides a rectangular opening through which the diepasses, the die being moved in the direction of the double arrow 7 bysuitable means (not shown).

The stationary part A includes a first pair of bending rails 8, 8 and asecond pair of bending rails 9, 9. The bending rails 8, 8 are spacedlaterally apart and are disposed in parallel relation while the bendingrails 9, 9 are also spaced laterally apart in parallel relation. Thebending rails 9, 9 are disposed vertically below the bending rails 8, 8and are positioned in right angular relation thereto. The bending railsare spaced apart in an adjustable manner depending upon the height ofthe box to be erected and are spaced vertically apart in the directionof motion of the die B.

The bending rails are curved at their inner faces so as to easilyreceive and fold up the walls of the box as the box is moved through theopening of the stationary part in contact with the curved inner faces ofthe bending rails.

Each of the bending rails is formed on its outer side with alongitudinally extending dove tail groove 10. Connecting links 14 aredisposed between the upper pair of rails and the lower pair of rails andare mounted as shown in FIGURE 5; Thus,- the links are mounted in thedove tail grooves by means of interior clamping members 11 and screws13. The connecting links are also connected to the lower rails 9 whichhave dove tail grooves 10 by means of the interior clamping members 16and screws 15. The screws 15 pass through vertical slots 15:; in theconnecting links, as shown in FIGURES 4 and 5, so that the verticaldistance between the upper pair of rails and the lower pair of rails canbe adjusted.

Thus, it can be seen that the width and length of the rectangularopening in the stationary part which is defined by the upper pair ofbending rails and the lower pair of bending rails can be adjusted so asto accommodate difierent sizes of blanks. The vertical space between theupper pair of bending rails and the lower pair of bending rails can alsobe adjusted so as to be substantially equal to the height of the box tobe erected.

A first pair of spring urged balls 17 and 18 is positioned directlybelow each of the bending rails 8 of the upper pair, as can be seen inFIGURES 2 and 4. The balls 17 and 18 are spaced apart and are disposedadjacent the inner surfaces of the bending rails 9, 9, as shown inFIGURE 4. A second pair of spring urged balls 19 and 20 is disposedbelow each of the bending rails 8 and the balls 19 and 20 are positionedat a height substantially equal with the lower edges of the lowerbending rails. The balls 19 and 29 are positioned between the balls 17and 18 and are substantially close together.

As shown in detail in FIGURE 2, each of the balls is guided in a sleeve21 which is screwed onto a screw bolt 22 and secured by means of a locknut 23. The screw bolts 22 are mounted in apertures in supporting straps24 and 25 and held in place by lock nuts 26. The straps 24 are providedfor the balls 17 and 18 while the longer straps 25 are provided for theballs 19 and 20, as can be seen in FIGURE 2.

By displacing a sleeve 21 along a screw bolt 22 it is possible to modifythe pressure exerted by the coil spring 30 on the balls, the balls beingheld from complete urgement out of the sleeves by the slightly inwardlybent outer ends of the sleeves, as shown in FIGURE 2. The coil springseats against the outer ends of the bolts.

The straps 24 and 25 are attached, as shown in FIG- URE 2, to the upperrails by means of clamping members 29 which are mounted in the dove tailgrooves in the upper rails, clamping and guide members 28 and screws 27;A strap can be adjusted by loosening a screw 27 so as to be displacedalong the axis of a rail 8. The straps are adjustable to position theballs along the rails depending upon the size of a box to be erected.

In using the device, a paper board blank is first placed by hand or bysuitable mechanical means upon the upper bending rails in such a waythat it is centered with the die B. In other words, the bottom wall ofthe blank 1 is positioned so that it covers the opening in thestationary part A. As the die moves downwardly, the end Walls 3 and tabs4 are f rst bent upwardly by being moved against the bending rails 8. Assoon as the bottom wall 1 comes within the range of the lower bendingrails 9, 9, the portions 3a of the end walls, which lie outside theslots 6, will be in the range of action of the balls 17 and 18 whichthen operate to push the portions 3a inwardly into the concave recesses31 of the lateral faces of the die facing the same, as shown'in FIGURE2. Thus, the slots 6 are open. While the balls 17 and 18 are stillactive to keep the slots 6 open, the side walls 2 come within the rangeof the-lower bending rails 9, 9. Asthese side walls2 are being erected,the tabs will slide from under the balls 17 and 18 into the slots 6.This operation is substantially terminated as soon as the base portionor bottom wall 1 reaches the lower edge o f the lower bending rails 9,9. At this point, the balls 19 and 20 push the flaps 3b inwardly to bendthem about the fold lines 30. The flaps 3b and the holding projectionsare thereby bent inwardly about the folding lines- 30.

While-the: preferred form of the present invention has been shown anddescribed herein, other forms can be realized ascome withinthe scope ofthe appended claims.

I claim:

1. A device for erecting of paper board boxes of the type having arectangular bottom and a pair of opposing end walls and a pair ofopposing side walls, said walls being connected to the bottom by foldlines, each of said side walls having a tab positionable at right anglesthereto to extend inwardly toward the end walls and having a lockingprojection and the end walls having vertical slots to receive the tabsand projections and having upper edges provided with hinged flaps intowhich the slots extend; said device comprising a stationary part havingan opening and a die movable in a rectilinear path through the openingto erect the box from a flat blank, said stationary part including afirst pair of bending rails disposed in parallel, laterally spacedrelation and a second pair of bending rails disposed in laterally,spaced parallel relation, the second pair of rails being verticallyspaced below the first pair and being in right angular relation thereto,the upper pair of bending rails serving to bend over the end walls andthe tabs of the side walls, and a plurality of freely rotatable springurged balls lying below the first pair of rails in substantially thesame vertical planes and being mounted to move transversely to thedirection of movement of the die, certain of said balls being arrangedintermediate the rails of the first and second pair and being adapted topush inwardly the portions of the end walls that are outside the slotsinto corresponding recesses in the die in order to open the slots toreceive the tabs, said tabs being moved into the slots by the bendingrails of the second pair which serve to fold up the side walls andcertain of said balls being disposed at a level substantially below thelower pair of bending rails to bend the flaps down and lock the tabs inplace by bending over the projections.

2. The combination of claim 1, wherein said bending rails of each pairare laterally adjustable relative to each other.

3. The combination of claim 1, wherein the first and second pairs ofbending rails are mounted for vertical adjustment.

4. The combination of claim 1, wherein the bending rails of the firstpair are connected to the bending rails of the second pair by connectinglinks and means mounting the links for vertical adjustment relative tothe pairs of rails and for adjustment along the longitudinal axes of therails of each pair.

5. The combination of claim 1, wherein the spring urgedballs are mountedin holders carried by straps that depend from the rails of the firstpair, said straps being adjustable vertically and along the axes of therails of the first pair.

6. The combination of claim 5, wherein the holders includemeans foradjusting the spring tension on the balls.

7. The combination of claim 1 wherein each of the spring urged balls ismounted in an outer end of a tubular holder with the inner end of thetubular holder being threaded onto a support member, and the springurging the ball being disposed within the tubular holder between theball and the support, with the adjustment of the tension of the springbeing accomplished by rotating the tubular holder with respect to thesupport.

References Cited in the file of this patent UNITED STATES PATENTS2,553,733 Acker May 22, 1951 2,798,416 Clement July 9, 1957' 2,832,270Pierce et a1 Apr. 29, 1958 2,921,507 Hedlund et al. Ian. 19, 19602,942,533 Atkinson June 28, 1960

